500kWp commercial solar PV cost in the UK (2026)
At 2026 prices, a 500 kWp commercial solar PV system costs £325,000 - £400,000 installed (excl. VAT). After 100% Full Expensing for limited companies, net cost is around 25% lower. Typical post-tax payback: 3.3-5.9 years.
500 kWp cost summary
| System size | 500 kWp |
| Installed cost range (2026, excl. VAT) | £325,000 - £400,000 |
| £ per Wp | £0.65 - £0.80 |
| Number of panels (450W modules) | ~1,100 |
| Roof area required | ~2,800 m² |
| Annual generation (UK avg) | 475,000 kWh |
| Best fit for | warehouse, factory, distribution centre, large supermarket, hospital, university |
| Best grant stack | Full Expensing + IETF (energy-intensive) or PSDS (public sector) + REGO + SEG |
Year-1 maths breakdown
Worked example for a limited company at the 25% main corporation tax rate, with typical self-consumption assumptions for this system size.
| Gross capex (mid) | £362,500 |
| 100% Full Expensing tax saving (25% CT) | -£90,625 |
| Net effective cost | £271,875 |
| Annual self-consumption (35%) | 166,250 kWh saving £36,575/year |
| Annual SEG export (65%) | 308,750 kWh earning £9,262 - £46,312/year |
| Total year-1 savings/revenue | £45,838 - £82,888 |
| Post-tax payback | 3.3 - 5.9 years |
Typical roof & site requirements for 500 kWp
- Unshaded roof area: ~2,800 m² needed for 1,100 × 450W panels
- Roof condition: 15+ years remaining life expected — older roofs may need refurbishment first (adds £30-300k depending on size)
- Roof structure: imposed load 12-25 kg/m² — modern portal-frame and composite roofs typically fine; some 1960s-80s structures need Cat 2 survey
- Electrical service: three-phase G99 connection required; rural sites may need DNO capacity study (5-11 weeks lead time)
- Planning: typically permitted development for commercial rooftop solar; listed buildings and conservation areas require consent
- Insurance: notify your insurer before installation; typical premium impact £150-£800/year additional
Best grant fit for 500 kWp
Recommended grant stack
Full Expensing + IETF (energy-intensive) or PSDS (public sector) + REGO + SEG
Use the free eligibility calculator for a personalised grant match against your specific sector, postcode and ownership structure.
Generation & savings model
This page uses conservative 2026 assumptions:
- UK average insolation: 950 kWh/kWp/year
- Tier 1 panel pricing: £0.18/Wp landed
- Inverter pricing: £0.07/Wp
- Mounting + BOS: £0.18/Wp
- Install + DNO: £0.15-£0.30/Wp depending on roof type
- SEG floor: 3p/kWh (regulatory minimum)
- SEG ceiling: 15p/kWh (best 2026 fixed-tariff rate)
- Self-consumption rate: typical for warehouse, factory, distribution centre, large supermarket, hospital, university load profile
500 kWp commercial solar · FAQs
How much does a 500 kWp commercial solar system cost in 2026?
At 2026 prices, a 500 kWp commercial solar PV system costs approximately £325,000 - £400,000 installed (excl. VAT). After 100% Full Expensing tax relief for a limited company at the 25% main CT rate, net cost is around £243,750 - £300,000.
What is the payback period for a 500 kWp commercial solar system?
With 35% self-consumption and SEG export tariffs of 3p-15p/kWh, a 500 kWp system typically pays back in 3.3-5.9 years post-tax (limited company at 25% CT). Higher tax rates (sole trader at 45%) compress payback further.
What size roof is needed for a 500 kWp system?
A 500 kWp system requires approximately 2,800 m² of unshaded roof area — around 1,100 modern 450W solar panels. Modern industrial portal-frame buildings, large warehouses and big-box retail typically accommodate this comfortably.
How much electricity will a 500 kWp system generate?
In the UK (average insolation), a 500 kWp system generates approximately 475,000 kWh per year. Self-consumption rate depends on your load profile — 35% is typical for warehouse, factory, distribution centre, large supermarket, hospital, university.
Which grants apply to a 500 kWp system?
Best grant fit for this size: Full Expensing + IETF (energy-intensive) or PSDS (public sector) + REGO + SEG. Always use the eligibility calculator for a personalised match.
Can I get finance for a 500 kWp solar system?
Yes — at this scale, asset finance / hire purchase is the most common route (5-7 year terms at 7-11% APR in 2026). For systems above 250kWp, operating lease and PPA are also viable. See finance routes.
Get a sized quote for your 500 kWp project
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